Yamaha FX Nytro 2008 Manuel D'atelier page 454

VALVES AND VALVE SPRINGS
11. Measure:
• Valve spring free length a
Out of specification → Replace the valve
spring.
12. Measure:
• Compressed valve spring force a
Out of specification → Replace the valve
spring.
b Installed length
13. Measure:
• Valve spring tilt a
Out of specification → Replace the valve
spring.
14. Inspect:
• Valve lifter
Damage/scratches → Replace the valve lift-
ers and cylinder head.
INSTALLATION
1. Deburr:
• Valve stem end
(with an oil stone)
5-36
ENG
Valve spring free length (intake and
exhaust):
39.57 mm (1.56 in)
<Limit>: 37.59 mm (1.48 in)
Compressed valve spring force
(installed):
112.30 ~ 129.30 N at 34.60 mm
(11.45 ~ 13.18 kg at 34.60 mm,
25.24 ~ 29.07 lb at 1.36 in)
Maximum valve spring tilt:
2.5°/1.7 mm (2.5°/0.07 in)